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Re: enable packing by default

From: Ivan Zhakov <ivan_at_visualsvn.com>
Date: Wed, 18 Jun 2014 18:03:27 +0200

On 16 June 2014 15:53, Stefan Sperling <stsp_at_elego.de> wrote:
> Stefan2 pointed out that format 7 is less efficient if packing is disabled.
> So to fully benefit from format 7 in the default configuration, users must
> currently run 'svnadmin pack' or edit fsfs.conf to enable packing after commit.
> Since format 7 adds locking support to pack, so it should be safe to trigger
> packing at any time.
> It looks like it makes sense to enable packing after commit by default
> for format 7 repositories. Any objections?
I strongly disagree with the proposed patch. With this patch every
1000th commit will take long time: because Subversion will have to
combine 1000 revisions to one file. That's means with 1mb revisions
Subversion will have to write 1gb to disk for the 1000th commit. This
cannot be done fast and during this time svn client will hang.

We cannot broke one of the current fundamental characteristics of
Subversion. The time of the commit should only depend on the size of
the committed data. It shouldn't depend on the cumulative size of the
previous 1000 commits!

The possible solutions are to pack incrementally after each commit or
trigger packing to be performed asyncronously (i.e. in background),
but I'm not sure if it's possible to implement easily.

Ivan Zhakov
CTO | VisualSVN | http://www.visualsvn.com
Received on 2014-06-18 18:04:13 CEST

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